Method and apparatus for the superficial conditioning food extrusions

ABSTRACT

Method and apparatus for the superficial conditioning of food extrusion, carrying out the steps of introducing a food extrusion ( 2 ) in a conditioning duct ( 3 ) for the superficial stabilizing of the extrusion ( 2 ); in a first section ( 4 ) of said duct ( 3 ), spraying the surface of the food extrusion ( 2 ) with a stabilizer in form of gel; and in a second section ( 6 ) of said duct ( 3 ), spraying the surface of the food extrusion ( 2 ) with a catalyst of said stabilizer.

The present invention refers to a method and to an apparatus for thesuperficial conditioning of food extrusions, in particular meat-baseextrusions in form of sausages, frankfurters and the like.

There are several known systems for conditioning the surface of saidextrusions, in order to manufacture sausage-shaped uncased extrusions,ready to be packaged, e.g. in tubs or in vacuum packages, and thendirectly consumed.

The methods most widely resorted to foresee the employ of vatscontaining a bath with collagenic substances. The extrusions, expelledfrom the machine compacting them in a cylinder-shaped and elongatedshape, are passed through said bath and subsequently dried prior topackaging.

This type of systems is unsatisfactory in several respects. In fact, thevats fill up a considerable space, which is detrimental to thecompactness of the extrusion apparatus, and are apt to gatherenvironmental pollution, due to the extrusions and to any agent externalto the apparatus. This compels the emptying of the vats, and the fillingthereof, with the entailed break in the production run and the poorefficiency in the employ of the fluids stabilizing the surface of thefood extrusions at issue.

An exemplary process of the state of the art is taught by InternationalAppln. WO 01/41576.

Moreover, it should be pointed out that the animal origin of thecollagenic substances might make consumers feel insecure.

The technical problem underlying the present invention is to provide amethod and an apparatus overcoming the drawbacks mentioned withreference to the known art.

This problem is solved by a method for the superficial conditioning offood extrusions, characterized in that it comprises the steps of:

-   -   introducing a food extrusion in a conditioning duct for the        superficial stabilizing of the extrusion;    -   in a first section of said duct, spraying the surface of the        food extrusion with a stabilizer in form of gel; and    -   in a second section of said duct, spraying the surface of the        food extrusion with a catalyst of said stabilizer.

Hereinafter, for stabilizer it is meant a substance capable of forming,onto the surface of the extrusion, a film compatible with foodconsumption, such as to provide sturdiness and strength to the surfaceand to the extrusion.

In a preferred embodiment of said method, the stabilizer comprisessodium alginate, carrageen, Xanthan gum, suitably mixed and optionallywater-diluted.

Spraying of the catalyst, that in a preferred embodiment of said methodcomprises calcium lactate, calcium chloride, lactic acid and optionallywater-diluted mixtures thereof, accelerates the film-forming reaction.The main advantage of the method according to the present invention liesin conditioning and stabilizing the surface of the extrusion within verylimited times and space, to then forward the extrusion to subsequenttreatments and to packaging.

The invention further refers to an apparatus for the superficialconditioning of extrusions comprising a closed conditioning duct housingthe extrusion, said conditioning duct being partitioned into a firstsection, fed by first superficial treatment means, and a second section,fed by second superficial treatment means.

The present invention will hereinafter be disclosed according to apreferred embodiment thereof, given by way of a non-limiting example andwith reference to the attached drawing, wherein FIG. 1 is a schematicsectional view of an apparatus for the superficial conditioning of foodextrusions according to the present invention, incorporated in a morecomplex extrusion apparatus.

With reference to FIG. 1, an apparatus for the extruding of foodextrusions is partially depicted and indicated with 1.

This type of apparatus is apt to produce extrusions, e.g., meat-baseones, outletted in form of a cylinder-shaped extrusion 2. Thisapparatus, not providing encasing, should comprise an apparatus for thesuperficial conditioning of the extrusion, in order to form asuperficial stabilizing film onto the surface thereof.

The apparatus for the conditioning, it also partially depicted,comprises a closed conditioning duct 3 housing the extrusion 2 inlettedfrom the extruding and free from any prior stabilization conditioning,merely optionally treated to aromatize the mixture of the extrusion 2.

The conditioning duct is partitioned into a first section 4, fed byfirst superficial treatment means 5, and a second section 6, fed bysecond superficial treatment means 6.

The first section 4 consists of a duct portion 3 inside which theextrusion flows, acquiring a section shape similar to the wall thereof.

Inside of this section 4 a stabilizer in form of gel is injected, inorder to uniformly cover the surface to be stabilized. The injectingtakes place by virtue of said first superficial treatment means 5feeding said first section 4 with gel at adjustable flow rate andpressure.

A higher pressure and, therefore, a higher flow rate, concur incompacting the extrusion 2 and in thickening the gel layer that, at asubsequent stage, will be turned to film.

The second section 6 consists of a duct portion 3 into which theextrusion 2 flows with a remarkable clearance between the surface to bestabilized and the wall of the duct 3. Said second treatment means 7comprises, located on said wall at the second section 6, a plurality ofnozzles 8 pressure-fed with a catalyst in liquid form.

The geometry of the second section 6 enables the complete spraying ofthe surface of the extrusion 2.

With reference now to the method for the superficial conditioning, itcomprises a step in which the extrusion 2 is introduced in said closedduct 3, in order to insert it in a restricted environment wherein theconditioning that will stabilize the surface of the extrusion 2 is to becarried out.

In said first section 4, the food extrusion 2 is sprayed with astabilizer provided in form of gel that is capable to form, prior to thesubsequent treatment, a sort of unstabilized film onto the surfacethereof.

The shape and the thickness of said film are adjusted varying thepassage section of the corresponding duct portion 3 and the feedpressure of the gel.

The stabilizer comprises sodium alginate, carrageen, Xanthan gum,optionally mixed and water-diluted. However, it is understood that thestabilizer may comprise equivalent surfactant substances.

However, these substances should be compatible with human consumption offood, i.e., meet the requirements of the standards on the matter. Thesame principle also applies to any further substance employed onto thesurface of the extrusion.

The method comprises the subsequent step, located at the second section6 of said duct 3, of spraying the surface of the food extrusion 2 with acatalyst of said stabilizer.

In this embodiment, the catalyst, provided in liquid form and sprayedand atomized onto the surface of the extrusion, comprises a mixture ofcalcium lactate, lactic acid, calcium chloride and optionallywater-diluted mixtures thereof. However, it is understood that thecatalyst may comprise equivalent surfactant substances.

Going back to the apparatus for the superficial conditioning, downstreamof said section 6 it comprises a roller conveyor 9. Located at saidconveyor 9 there may be, besides means for portioning the extrusion 10in form of partitioning members 11, further equipments (not shown) forthe subsequent superficial treatment of the extrusion 2.

Among said equipments, the following are mentioned:

-   -   an equipment for the superficial rinsing of the extrusion,        comprising a rinsing bath, optionally provided with bath        agitating means, or with spraying means—the rinsing takes place        with water;    -   an equipment for the compacting of the extrusion with means        uninjurious to the newly-conditioned surface of the extrusion,        e.g. by ultrasounds; and    -   an equipment for the superficial drying of the extrusion,        operating with one or more forced flows of cold air.

It is understood that the latter two equipments may operateconcomitantly.

Said equipments correspond to as many steps of further conditioning,superficial and not superficial, of the extrusion:

-   -   a step of rinsing the surface of the extrusion by water        immersing or spraying;    -   a step of compacting the extrusion via the surface thereof, by        ultrasound application; and    -   a step of superficial drying of the extrusion by exposure to one        or more cold air flows.

Subsequently to these steps, that usually ensue the portioning of theextrusion, the extrusion portions may be forwarded to furthertreatments, e.g., smoking, cooking, etc. or to packaging.

To the abovedescribed method and apparatus for the superficialconditioning of food extrusions a person skilled in the art, in order tomeet further and contingent needs, may effect several furthermodifications and variants, all however encompassed by the protectivescope of the present invention, as defined by the appended claims.

1-13. (canceled)
 14. A method for the superficial conditioning of foodextrusions, comprising the steps of: introducing a food extrusion in aconditioning duct for the superficial stabilizing of the food extrusion;in a first section of said duct, spraying the surface of the foodextrusion with a stabilizer in form of gel; and in a second section ofsaid duct, spraying the surface of the food extrusion with a catalyst ofsaid stabilizer.
 15. The method according to claim 14, wherein saidstabilizer comprises at least one of the following substances: sodiumalginate, carrageen, and Xanthan gum, and, optionally, water-dilutedmixtures thereof.
 16. The method according to claim 14, wherein saidcatalyst comprises at least one of the following substances: calciumlactate, calcium chloride, and lactic acid, and, optionally,water-diluted mixtures thereof.
 17. The method according to claim 14,comprising a step of rinsing the surface of the extrusion by waterimmersing or spraying.
 18. The method according to claim 14, comprisinga step of compacting the extrusion via the surface thereof, byultrasound application.
 19. The method according to claim 14, comprisinga step of superficial drying of the extrusion by exposure to one or morecold airflows.
 20. An apparatus for the superficial conditioning ofextrusions comprising a closed conditioning duct housing the foodextrusion, said closed conditioning duct being partitioned into a firstsection, comprising first superficial treatment means, and a secondsection, comprising second superficial treatment means.
 21. Theapparatus according to claim 20, wherein the first section consists of aclosed duct portion inside which the food extrusion flows with a minimumclearance between the surface to be stabilized and the wall of theclosed duct.
 22. The apparatus according to claim 21, wherein inside ofthe first section a stabilizer in form of gel is injected, in order touniformly cover the surface to be stabilized, the injecting taking placeby virtue of said first superficial treatment means feeding said firstsection gel at adjustable flow rate and pressure.
 23. The apparatusaccording to claim 20, wherein the second section consists of a closedduct portion inside which the food extrusion flows with a remarkableclearance between the surface to be stabilized and the wall of theclosed duct, said second treatment means comprises a plurality ofnozzles located on said wall at the second section and pressure-fed witha catalyst in liquid form.
 24. The apparatus according to claim 20,comprising an equipment for the superficial rinsing of the extrusion,comprising a rinsing bath, optionally provided with bath agitatingmeans, or with spraying means.
 25. The apparatus according to claim 20,comprising an equipment for the compacting of the extrusion with meansuninjurious to the surface of the newly conditioned extrusion, e.g. byultrasounds.
 26. The apparatus according to claim 21, comprising anequipment for the superficial drying of the extrusion, operating withone or more forced flows of cold air.